Time series, months and sequence

Hi everyone,

I have 12 series:

x1 = [1990M1, 1991M1, 1992M1 .....2020M1]

x2=[1990M2, 1991M2, 1992M2 ...2020M2]

...

x12=[1990M12, 1991M12, 1992M12 ...2020M12]

Now I would like a time sereis:

x= [1990M1, 1990M2, 1990M3 ...2020M12].

Please give me a hint.

Many thanks,

Bao

[Mehmed Saad]

if they are of same length just put

y = [x1;x2;x3;x4;x5;x6;x7;x8;x9;x10;x11;x12];
x = y(:,1);

[Nguyen Bao]

Thanks, but this is not the solution.

Answer 1

[Ameer Hamza]

First, you should avoid creating variables names like x1, x2, ..., xn. This thread explains the issues with this approach in detail: https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Now, if you want to correct this issue by combining all these values in a single array, then you can use eval(). Note that using frequently using eval() in your code is not a very good idea and should be avoided, but you can use it once to fix the initial mistakes. This code shows an example.

x1 = [1 2 3];
x2 = [4 5 6];
x3 = [7 8 9];
x4 = [10 11 12];
x5 = [13 14 15];

x = [];
for i=1:5 % numbers of the x variables
    eval(['x = [x; x' num2str(i) '];']);
end
x = x(:)';

[Nguyen Bao]

Thanks Ameer,

In fact, I would like to see:

x= [1 4 7 10 13 2 5 8 11 14 3 6 9 12 15]

This is because, I have 12 balanced separate series contain data of 12 months for several years, now I want to put them together to get a signle time series for those years continuously. For example, x1 contains values in Jan from 1990 to 2020, x2 is in Feb from 1990 to 2020 ....Thus, I want to see a series x = 1990 Jan, 1990 Feb .....2020 Dec.

Cheers,

[Ameer Hamza]

Nguyen, please try the updated code.

[Nguyen Bao]

Perfect, thanks Ameer.